1. Field of the Invention
The present invention relates to a gaming machine such as a slot machine, a pachi-slot machine, and a pachinko machine, and also relates to a game system including a gaming machine and a server that is connected in communication with the gaming machine.
2. Description of Related Art
In a gaming machine such as a slot machine and a card game machine, when a game medium such as a coin is inserted into the gaming machine to start a game, an internal lottery is performed, and the game result is displayed based on the result of that internal lottery. For example, in a slot machine, a symbol determined by the internal lottery is stopped and displayed on a reel, and in a card game machine, a card of specified type determined by the internal lottery is displayed. Then, based on the game result, a predetermined number of game media are paid out.
In such a gaming machine, a probability of offering an advantageous game result to a player, e.g., the probability of a win on a pay line, is set to a predetermined value. In this case, the winning probability converges at a predetermined value, for example, a payout rate is 80%, after quite a few games are performed. This causes problems in which many game media are obtained even though few game media are spent, and in which only a few game media are obtained even though a great number of game media are spent. Therefore, gambling orientation is increased to add amusingness to games, whereas a player loses expectations for games when it is difficult to obtain the advantageous game result, which can cause a game shop having such a gaming machine to lose customers.
In order to prevent a player from losing expectations for games, various techniques are proposed. For example, there is a technique to automatically conduct a payback system in which game media such as inserted coins are partially preserved to pay back afterward (see JP-A-2003-117070). According to the payback system, when the amount of lost credits equal to or more than an upper limit, the preserved game media are offered to a player. Furthermore, there is a technique in which an additional coin insertion slot for insurance is provided, and three insurance coins are inserted thereto to apply an insurance function. When a predetermined number of coins are inserted into a gaming machine during a game, insurance coins are paid out (see JP-A-4-244178).